Grit blasting machine



Aug. 13, 1968 R. A. M. SCHENCK GRIT BLASTING MACHINE 2 Sheets-Sheet 1 Filed Aug. 30, 1965 K me x m M R h 0 We Mn 5 A w RY Aug. 3, 1968 R. A. M. SCHENCK 3,396,492

GRIT BLASTING MACHINE 2 Sheets-Sheet 2 Filed Aug. 30, 1965 INVENTOR. /?.A. MSchencK 6 Lu-aux ATTORNEg United States Patent 3,396,492 GRIT BLASTING MACHINE Robert A. M. Schenck, Wilrijk, near Antwerp, Belgium, assignor to Mercantile Marine Engineering & Graving Docks Co., Antwerp, Belgium Filed Aug. 30, 1965, Ser. No. 483,713 Claims priority, application Belgium, June 15, 1965, 665,425 4 Claims. (Cl. 518) ABSTRACT OF THE DISCLOSURE A grit blasting machine includes a vehicle, a displaceable L-shaped bracket resting with its horizontal arm on the rolling elements of the vehicle and having a vertical arm which extends downwardly with respect to the vehicle. A grit projection device is mounted on the vertical arm and is displaceable along this arm. 'Means are provided for bringing the projection device into contact with the surface to be grit-blasted.

The present invention relates to a machine for the working of the process according to my patent application Ser. No. 213,784, filed July 31, 1962, now Patent No.

3,262,228, dated July 26, 1966. The object of this ma chine is the sand-blasting or carrying out any similar treatment of metal surfaces by projecting thereon small particles of considerable hardness at a high velocity.

The abovementioned process is mainly characterized by applying, against the surface to be processed, the chamber of the projection device; in securing a tight contact between aforesaid chamber and aforesaid surface and in moving the chamber in question all along aforesaid surface which is kept immovable, in order to sweep its entire area.

Aforesaid application has also disclosed a machine specially conditioned for applying this characteristic process. This machine, which may assume very different sizes and shapes, mainly consists in a combination of at least one vehicle; a device for projecting small hard particles; between aforesaid projection device and aforesaid vehicle, a hinged support making it possible to bring aforesaid projection device into contact with the surface to be processed; a filtering device carried by aforesaid vehicle and, linked with aforesaid projection mechanism, a means of propulsion and means for ensuring the drive, the control and the safety.

According to this general disposition of the machine, the vehicle may assume any shape and any dimension appropriate to local conditions, without interfering with the machine or with the basic design. In fact, the essential feature which conditions the construction of said vehicle in accordance with the cleaning problem to be carried out, is and remains the necessity of maintaining a tight permanent contact between the surface to be processed and the chamber of the projection device, as well as the necessity of moving this chamber under such conditions over practically the whole area of the metal surface under treatment.

In the embodiment described in detail and merely by way of example in aforesaid application, the vehicle is designed for being moved on the bottom of the dry dock, whereby the vehicle in question carries an upper structure forming in fact a telescoping scaffolding extending upward and forming the support along which the projection device can be moved in such way that, by the combination of this upward displacement with the horizontal displacement of the vehicle, it is possible to sweep a considerable area with the projection device. On the other hand, as aforesaid structure is designed for enabling the 3,396,492 Patented Aug. 13, 1968 Ice vehicle to move sideways with respect to the plane defined by the orthogonal co-ordinates of aforesaid movements, it is easily possible for aforesaid projection device to maintain its contact with the curved surfaces or skew surface of any kind.

Although the description and the claims filed in said application certainly do not limit the invention to the construction of such a machine with a vehicle which must necessarily move about on the bottom of the dry dock, the present improvements aim at justifying the general character of the means described in aforesaid application by disclosing an application which, althoughparticular, is strictly aiming at the same functions and technical results as those which have been disclosed in aforesaid application.

According to these improvements, the actual projection machine and the process being applied are technically similar to those which were described in the abovementioned application. On the other hand, the vehicle is designed so that a structure forming the support of aforesaid projection device and carried by the actual vehicle, extends downward. This characteristic disposition makes it possible to apply the process and the machine conforming to aforesaid application, under very special circumstances, and namely when the free space between the surface to be processed and the adjacent wall of the dry docks is comparatively narrow and, at any rate, inadequate for housing and moving therein the machine as a whole.

On account of this novel disposition, and namely in applying aforesaid process and machine for sand-blasting ship hulls, it will be possible to move the vehicle on the edge of the dry dock sidewalls, whereby only the projection device and the structure which supports it and is connected to the actual vehicle are being inserted in this comparatively narrow space. This characteristic arrangement provides a further extension of the field of application of the means disclosed in aforesaid application.

An example of such special embodiment is described hereafter with reference to the appended drawings, of which:

FIGURE 1 is a side view of a sand-blasting apparatus according to the aforesaid patent, more particularly suitable for narrow spaces;

FIGURE 2 is a top view of the machine illustrated in FIGURE 1.

In this form of embodiment, the initial combination consists of the trolley A, a projection device B and the filtering device C.

On the trolley A, there is the chassis 1 supported by two sets of wheels of which either one or both may be driving wheels.

The filtering device C is carried by aforesaid trolley and also mainly designed as described in aforesaid application or in any other technically equivalent manner.

The projection apparatus B is also practically identical to that which has been described in aforesaid application.

Between aforesaid trolley A and the projection apparatus B, there has been inserted the particular structure which forms the essential object of the present invention and which makes it possible to apply the projection device B even in comparatively narrow spaces.

This structure comprises a bracket 2 having the horizontal beam 3 which rests on cross-beams 5 of aforesaid trolley by means of rollers 4. This same horizontal beam is duly guided in .order to prevent the structure which carries the projection device B from tipping over. The vertical beam of aforesaid bracket is practically closed by two U-shaped uprights 6-7 belonging to a lattice construction 8 connected to aforesaid horizontal beam 3 by pins 9. Between aforesaid uprights 6-7 there is a crab 10 with an upper platform 11 and a lower platform 12; a connecting rod 13 is hinged at both ends, respectively to the lower 3 platform 12 and the projection device B by means of the pivots 1415 respectively. The rear part of aforesaid projection apparatus B is fitted with a seat 16 which can accommodate a conductor, in the same way as aforementioned platforms 11-12, for carrying out supervision, maintenance and repairs. Aforesaid crab 10 is suspended to two cables 17 which pass over guiding rollers 18-19- 20-21 and the other end of which is wound on a winch 22 carried by aforesaid horizontal beam 3. The projection device B is linked to the filtering device C by a hose 23. Aforesaid beam 3 also carries a control table 24 and various additional or accessory apparatus.

In the present construction, the trolley A moves on the upper edge-stone or rim 25 of a dry dock side wall 26. In the example illustrated diagrammatically in FIGURES 1 and 2, the apparatus is equipped for scouring the hull of a ship 27. Due to this original arrangement, the projection device B can be moved in three orthogonal directions and hence remain in constant tight contact with the surface to be processed. The distance between this surface 27 and the inner face of the side wall 26 of the dry dock may be comparatively quite narrow without impairing in any way the scouring operation.

It is quite evident of course, that this kind of embodiment can be applied to horizontal and vertical structures of almost any shape, without exceeding the scope of the present invention.

What I claim is:

1. A sand blasting machine comprising a vehicle, rollers carried by said vehicle, a displaceable L-shaped bracket having a horizontal arm resting upon said rollers and a vertical arm extending laterally to and below said vehicle, a projection device, means moving said projection device along said vertical arm, and said projection device being shiftable into an operative position.

2. A sand blasting machine according to claim 1 comprising a control table carried by said horizontal arm.

3. A sand blasting machine according to claim 1 wherein said moving means comprise a winch carried by said horizontal arm, rollers carried by said arms, a crab connected with said projection device, and cables wound upon said winch and extending over the last-mentioned rollers. said crab being suspended from said cables and being guided by said vertical arm.

4. A sand blasting machine according to claim 3 comprising a seat carried by said projection device, an upper platform carried by said crab and a lower platform carried by said crab.

References Cited UNITED STATES PATENTS 2,729,918 1/ 1956 Van Denburgh 51-8 2,836,013 5/1958 Koenig 51-8 3,015,913 1/ 1962 Anderson 51-9 3,262,228 7/ 1966 Schenck 51--9 LESTER M. SWINGLE, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,396,492 August 13, 1968 Robert A. M. Schenck It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 5, "Antwerp, Belgium" should read Naamloze Vennootschap, Hansadok, Antwerp, Belgium, a company Signed and sealed this 17th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

